Event creator and assistance confirmation

Hi all,
This is my first blog at wP.com and I'm starting a new blog. My idea is to make a kind of event maker where my friends can say: "Ok, I'll go/ No I won't" and all the other people can see how many people and who will assist to this event.
It would be like Facebook event.
I'm planing to use it for a football team to see how many people will come and everybody must know it.

There isn't one in WordPress.com, but there IS for http://Buddypress.org and http://wordpress.org I believe. This is a blog, not a social networking site per se. You could always just do it in the comments, or post a poll from Polldaddy.